The role of the Genetic Analysis and Sample Handling Core is: 1) To extract DMA from buffy coat and cheek cell samples from the nested case-control studies, measure and adjust DNA concentrations, and track and plate these specimens prior to genotyping. 2) To provide fast, efficient, and accurate genotyping to Project investigators at the lowest possible cost. 3) To identify, aliquot, and distribute for laboratory analysis plasma samples for biomarker analyses. During the next grant cycle the Core will conduct genotyping for germline polymorphisms in the MTHFR, glutamate-cysteine ligase, estrogen and progesterone receptor genes and additional polymorphisms in the one-carbon metabolism pathway (Project 1), MTHFR, MTRR, and IGF pathway genes, and additional polymorphisms in the one-carbon and COX-2 metabolism pathways (Project 2), and MTHFR and IGF pathway genes (Project 3). Germline DNA will be extracted from stored buffy coats and cheek cell samples. Plasma samples will be aliquotted and distributed to participating laboratories. This work will include analysis of over 138,000 assays (polymorphisms x subjects) for project 1,141,000 assays for project 2 and over 102,000 assays for project 3.